Rubus L. Bramble
Nancy Tilden Campbell
Rosaceae Rose Family
The genus Rubus was described by Carl von Linnaeus in Species Plantarum in 1753. He identified two European species of blackberries and began one of taxonomy's largest studies. It was eventually named Batology. As many as 300 species have been described as well as 300 microspecies and forms (Gorer, 1976). Wilhelm Olbers Focke did much of the work on the taxonomy of Rubus and published several studies (1910-1914) in which he divided the genus into 12 subgenera (Jennings, 1988). The plants are small to tall shrubs with a relatively shallow root system and woody stems called canes. These canes can be either erect or trailing. The leaves are most commonly compound and alternate with 2-5 leaflets. In some tropical species the leaves are simple palmate. The leaf edges in U.S. species are serrate (Jennings, 1988). Most species have thorns, hence the name Brambles. They flower in spring and early summer, the petals ranging in color from white to shades of pink and most species produce fruit composed of a receptacle, or torus, and drupelets in early summer to fall. The fruits are generally black, red, or purple, although some species produce yellow fruit (Gorer, 1976).
Almost 300 species have been described. Included is a list of some of the more common ones. It was compiled from works by Coats (1992), Gorer (1976), Jennings (1988), Agnello et al (1989), and Van Royens (1969). More complete lists can be found in the Manual of Vascular Plants of Norheastern United States and Adjacent Canada by Henry A. Gleason and Arthur Cronquint (1991). Identification is based on differences in leaves, canes, flowers, and fruit. The Gleason book has an excellent key to identify North American species (pp 249-250). The two best known members of the species are the blackberry and the raspberry. Blackberries are in the subgenus Eubatus. The most abundant wild blackberry in the Eastern U.S. is the common blackberry,R. argutus (Alderman, 1997). It has spread and hybridized extensively as forests have been cleared for cultivation (Agnello et al, 1989). Raspberries are in the subgenus Idaeobatus. The American Red Raspberry, R. idaeus strigosus, can be distinguished from R. argutus on the basis of fruit. Raspberries are usually red and separate from the torus when ripe. Blackberries are usually black and do not separate from the torus. Another difference is that the American red raspberry is more tolerant to cold and can grow farther north than R. argutus (Agnello et al, 1989).
The fruits of brambles, both raspberry and blackberry, were used by ancient Greeks for food and medicinal purposes. They were first cultivated in Europe in the 16th century, and were brought to the U.S. in the late 1700's. They have become a large food crop and are valued as ingredients in jams, jellies, sauces, pies, and wines, and more recently, yogurt and juice blends. They are high in vitamin C and fiber and contain ellagic acid which is an anticarcinogenic agent (Agnello et al, 1989). Wild species provide food and shelter for birds and other wildlife as well as protection for seedlings of other plants (Alderman, 1997). The typical life cycle is described on the page concerning the Red Raspberry.